Agent payments and commerce protocols
| Protocol | Origin | Status (2026-10-02) |
|---|---|---|
| AP2 Agent Payments Protocol | Google, announced 2025-09-16 with 60+ partners | Donated to the FIDO Alliance 2026-04-28; v0.2 adds “human not present” payments and Verifiable Intent (with Mastercard) |
| ACP Agentic Commerce Protocol | OpenAI and Stripe (founding maintainers) | Open, Apache 2.0, marked Beta; latest spec version 2026-04-17 |
| UCP Universal Commerce Protocol | Google and Shopify, announced at NRF 2026-01-11 | Open-source (Apache 2.0); versioned releases v2026-01-11, 01-23, 04-08 and v2026-08-25; governed by its own Governing Council (Google, Shopify; Stripe joined 2026-04-28) and a Technical Committee expanded to 16 seats on 2026-04-24 (Amazon, Meta, Microsoft, Stripe, Salesforce added); vertical councils for Food, Lodging, Payments; Lodging Booking in draft 2026-09-25 |
ACP and Instant Checkout
ChatGPT Instant Checkout (launched 2025-09-29 with Etsy) was built on ACP. It was retired in March 2026: OpenAI said the first version “did not offer the level of flexibility” it wanted, and on 2026-03-24 launched a discovery-first shopping experience where merchants handle checkout in their own sites or apps (CNBC headline and secondary reports). ACP itself remains: merchants share product feeds; specs cover Agentic Checkout, Delegated Payment and Feeds. See chatgpt-instant-checkout.
Relationships
UCP builds on REST/JSON-RPC, OAuth 2.0 and interoperates with AP2, a2a-protocol and model-context-protocol. AP2 is part of Google’s “A2 family” with A2A. Unlike AP2 (FIDO Alliance) and A2A (Linux Foundation), UCP has not been handed to a neutral foundation; it runs its own councils (no Linux Foundation handover found).
Resolved 2026-10-02: AP2 announcement date 2025-09-16 (multiple reports); Instant Checkout retirement is reported as March 2026 (exact day not published; OpenAI discovery-first relaunch 2026-03-24); UCP governance as above (ucp.dev announcements).
Sources
- https://blog.google/products-and-platforms/platforms/google-pay/agent-payments-protocol-fido-alliance/ (2026-09-30)
- https://github.com/agentic-commerce-protocol/agentic-commerce-protocol (2026-09-30)
- https://developers.openai.com/commerce (2026-09-30)
- https://ucp.dev (2026-09-30)
- https://www.cnbc.com/2026/03/24/openai-revamps-shopping-experience-in-chatgpt-after-instant-checkout.html (headline via search; page blocked, 2026-09-30)
- https://www.hypotenuse.ai/blog/chatgpts-instant-checkout-the-next-phase-of-agentic-commerce (secondary, 2026-09-30)
- https://www.getpassionfruit.com/blog/what-is-google-s-ucp-update-carts-catalogs-and-loyalty-in-ai-shopping (secondary, 2026-09-30)
- https://ucp.dev/documentation/announcements/ (2026-10-02)
- https://www.digitalcommerce360.com/2025/09/19/google-ai-payments-protocol-ap2/ (2026-10-02)
- https://github.com/Universal-Commerce-Protocol/ucp/discussions/379 (2026-10-02)